Sauer-Danfoss Inc. has released Sauer-Danfoss' D Series cast iron fan drive gear motor. The motor offers an integrated valve solution to match fan speed to cooling demand with the additional capability to reverse fan rotation for radiator cleaning. The D Series motor offers the pressure, temperature, and radial load capabilities of a piston motor with the compact size, contamination resistance and cost advantages of a gear motor.

The cast iron construction makes it suitable for applications requiring higher pressures, temperatures, and duty cycles. The reversing function integrates a solenoid operated directional control valve to reverse fan rotation and a proportional relief valve to regulate fan speed. The directional control and pressure relief valves are available in two flow ranges minimizing pressure losses in the system.